I had a bit of a hitch last week when I used a CAS! switching program and it wiped out my game.  I lost everything - my hoods, families, customized extra sims - all gone. 

Well, MOST of it has been restored due to my paranoia in backing up the majority of my customizations.  I still don't have my old hoods and their respective residents, but they can be rebuilt and restored over time.  The only truly sad part is now I have to find either of the witches again to get my witch sim back into the mix.  I got lucky and made contact almost instantly this last time, but I don't think I'll be able to repeat that scenario any time soon - darn it....